00381nam a2200169Ia 4500008004100000041001200041082001000053082001100063100002200074100001100096245003100107260001100138260000900149260000900158650002700167650001700194150909s9999    xx            000 0 und d  aEnglish  a631.4  bGOV/SO  aGovinda Rajan S V  eAuthor  aSoil and crop productivity  aBombay  bAsia  c1971  aAgricultural chemistry  aSoil Science